I have a Mac Mini with OS X Tiger. I occasionally get a random volume icon that pops up on my monitor. When it happens the sound quits. The slide bar in the volume icon on the menu bar is all the way at the bottom and when I try to move it up manually, it just goes right back down to the bottom. The only way to get rid of it it is to shut down the computer and power it up again. Restarting the computer usually does not remove it. Anybody have any suggestions?